Question

Решите уравнение: 9x^2-7x-2=0 , 7x^2-28=0

Answer 1

Ответ:

Объяснение:

1) 9x² - 7x - 2 = 0

D = b² - 4ac = 49 - 4*9*(-2) = 121

√D = 11

x = (-b ± √D)/2a

x₁ = (7 + 11)/18 = 18/18 = 1

x₂ = (7 - 11)/18 = -4/18 = -2/9

2) 7x² - 28 = 0

7x² = 28

x² = 4

x = ±√4

x₁ = 2

x₂ = -2

Answer 2

Ответ:9x^2-7x-2=0

D=в^2-4ас=7^2-4×9×(-2)=49+72= 121

=11

X1=11+7/2=9

X2=11-7/2=2

7x^2-28=0

7x^2=28

X^2=28÷7

X^2=4

x=+2,-2

Объяснение: